POS1399 THE INTEREST OF DOPPLER ULTRASOUND IN THE EVALUATION OF THE CARPAL TUNNEL SYNDROME SEVERITY
Authors: N. El Amri, S. Jriri, S. Guizani, K. Baccouche, N. Mahdhi, E. Bouajina
Journal: Annals of the Rheumatic Diseases (2022)

Background Several studies have proven the value of Doppler ultrasound (DpUS) in the diagnosis of carpal tunnel syndrome (CTS) with satisfactory sensitivity and specificity. Yet, unlike the Nerve Conduction Studies (NCS), the interest of this technique in the severity diagnosis in CTS remains uncertain to this day. Several studies have focused on this subject. However, the morphological signs of gravity are not yet consensual. Objectives Compare US data with clinical and electromyographic data in order to determine the place of DpUS in the severity diagnosis in CTS. Methods A bicentric cross-sectional study including patients with uni or bilateral CTS, confirmed by NCS, referred from the plastic surgery department. All the patients underwent a clinical examination, a NCS of both hands as well as a DpUS of the wrists by the same rheumatologist. Results After screening and application of all exclusion criteria, a total of 72 wrists of 47 patients were included. The median age was 54,23 ± 11 years [21-77 years] and 89,4% of wrists were from female patients. Hand numbness was the most frequent functional sign (94.4%) and the Phalen sign was the most noted examination sign (73.6%). Clinically, the patients presented respectively 32 mild, 14 moderate and 26 severe lesions. According to the NCS, there were 18 mild, 21 moderate and 33 severe CTS with 73.6% of the wrists with sensorimotor impairment. On US, the hypoechoic image was the dominant qualitative sign (84.7%). Regarding the quantitative measures, the mean Median Nerve (MN) cross sectional area (CSA) was 14.5 mm2 [9-30 mm2] and the mean flattening index was 3 [1.8-8.92]. Intraneural hypervascularisation was present in 57 writs (79,2 %). Statistically significant associations were detected between the MN CSA and both history of diabetes mellitus (p=0.045), diabetes duration (p=0.040) and disease duration (P=0.021). But there was no association between MN CSA and age (p=0,406), gender (p=0,690) and BMI (p=0,414). the mean MN CSA during mild clinical stage was 13.5 mm2. For moderate stage it was 17 mm2 while for severe stage it was 15 mm2.No relationship was found between US quantitative and morphological parameters and clinical severity grades. We detected significant correlation between MN hypervascularization and the CTS severity grades on NCS (p=0,044). For the other qualitative US signs, there was no statistically significant difference between the different grades of electromyographic severity (Notch sign (p=0.364), Hypoechoic image (p=1.000), Disappearance of the fascicular aspect (p=0.248), Decreased mobility of the tunnel contents of the canal during wrist movements (p=0.140)). the mean MN CSA during mild electromyographic stage was 13 mm2. For moderate stage it was 14 mm2 while for severe stage it was 15 mm2 and We did not find a statistically significant difference in MN CSA (P=0.494) between the different grades of severity of CTS on NCS. There is no statistically significant association between qualitative US signs and the type of NCS impairment; pure sensory or sensorimotor. However, we found a significant association between the MN CSA and pure sensory or sensorimotor damage on NCS (P=0,009). Conclusion MN DpUS could be a complementary procedure to the clinical examination which allows, in addition to the positive diagnosis, to evaluate the severity of the CTS based on the MN CSA and the intraneural vascularization in power Doppler. References [1]Bouchal S, Midaoui AE, Berrada K, Zahra AF, Aradoini N, Harzy T, et al. Comparaison des données de l’échographie par rapport à l’électroneuromyogramme dans le diagnostic de syndrome de canal carpien. Pan Afr Med J [Internet]. 25 sept 2019 [cité 15 oct 2020];34.Mohammadi A, Afshar A, Etemadi A, Masoudi S, Baghizadeh A. Diagnostic value of cross-sectional area of median nerve in grading severity of carpal tunnel syndrome. Arch Iran Med. nov 2010;13(6):516‑21. Disclosure of Interests None declared